Improvement in sewing-machines



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OfJUNKER. Sewing-Machine.

No. 217,112. Patented July1, 1879.

N.PETERS, PHOTO LITNOGEAPHEK WMHINGTON. D C

3 Sheets-Sheet 2 O. JUNKER.

v v Sewing-Machine. No. 2I7,-112. Patented July 1, 1879.

U IT D STATEsfPATE T OFFICE.

CARL JUNKER, 0F cARLsnUHE, BAD N, GERMANY.

lMPROVEiMENT IN EwmemAci-nmzs.

Specification forming part of Letters Patent N 0. 217,112, dated July 1, .1879; application filed July 2-3, 1878; patented in England, May 31, 1878, and in Germany, July 30, 1878.

To all'whom itmay concern:

Be it known that I, CARL J UNKER, of Carlsruhe, Germany,have in vented certain new and useful Improvements in Sewing-Machines, of which the following is a specification. This invention relates to sewing-machines;

spool-winder, and in an improved combination of devices for securing and permitting the ready removal of the shuttle-cover, all of which will be fully hereinafter described in detail. I p In the accompanying drawings, in which similar letters of reference indicate like parts,

vation of the machine.

section through A B, Fig. 3. Fig. 3 is a side View of the machine with the-cam-guard in section. Fig. 4 is a top View of the machine. Fig. '5 is a front elevation of the machine. Figs. 6, 7, and 8 show the locking device for the'shuttle-cover.

a is the standard, which is bolted to the bedplate, or may be cast in one piece with the same. This standard carries the following parts: first, the needle-arm c, andthrough the same the block it and the needle-bar as,- second, the shaft r, with its collars g, cams f and f, and chain-wheel 11; third, the shuttle-arm d, with the forked shuttle-seat; fourth, the shuttle-race c, with the cloth-plate l, needle-plate q, cover u, and feed-bar m fifth, the adjustable bearing 70, with the chain-Wheel h; sixth, the bobbin-winder n, with its support 8; seventh, the

I lower tension or thread brake w, needle-bar thread guide or brake 10 and the main tension apparatus 20 eighth, the presser-foot.

By means of the chain p, the hand-wheel h revolvesthe chain-wheel 2', and thereby the shaft r, on which the wheel iis mounted. The shaft 1' carries two cams, f and f, the cam f imparting motion to the shuttle arm 01, and the cam f to the needle-bar arm 0. The shuttle-arm d, Figs. 2 and 3, is a bell-crank lever, the short arm of which carries at its end the roller 01, projecting into the groove of cam f. The end of the long arm is forked, and supports the shuttle in the usual manner.

The needle-bar arm 0 is pivoted at j to the f acting on the roller c, Figs. 2 and 3.

The forward end of the swinging needle-bar arm is forked, a small square block, t, Fig. 1, fitting into this square fork. This blocktis and the improvements consist in an approved 1 construction of feed device,in anovel adjustable attached to the needle-bar 00' by means of a screw pin or bolt in such a manner that it is free to turn around the pin. I

To prevent theneedle bar from turning around its axis, a small pin projects from the block it, and passes into a socket at the inner end of the fork. During the operation of the 1 machine the block t slides backward and forand which reprcsentahand-machine embodyng my improvements, Figure 1 is an end ele- Fig. 2 is a plan of the principal operating parts, with the cloth-plate l removed, and the standard and needle-arm in ward in the fork, and the pin attached to it shares its motion,the socket in the arm acting as a guide.

In front of the shuttle-race c the feed-bar m is secured by means of a screw, m through a slot in the feed-bar, in such a manner as to admit of a reciprocating motion in a horizontal direction, while it may at the same time vibrate aroundthe screw m.

The feed-bar is, by preference, cut from a sheet of: steel, and then bent into the shape shown in the drawings, the thicknesses of the part bearing on the eccentric r being doubled by bending, as is also that part through which the screw m passes, which serves for regulatr ing the length of the stitch. By placing the eccentric r in front of r, I am enabled to make the feed-bar in this manner.

The toothed feed-dog m is adjustably attached to the feed-bar m. A spring, m, returns the feed-bar to its position. When the set-screw m is screwed out as far as the pin m near its end allows it to go, the machine will make the longest possible stitch, and the farther the screw m is turned in the shorter is the stitch. The toothed feed-dog, however, always returns to the same startingpoint before it is moved upward and forward, whatever the extent of this motion or the length of the z-titch may be. A small piece of leather or other suitable material is inserted into the outer end of the slot in the feed-bar to, through which the screw m passes, whereby noise during the return motion of the feed-bar is prevented. The toothed feed-dog m is vertically ad j ustable on the feed-bar by means of a screw,

m, which passes through a slot in said bar,

and engages in a screw-threaded hole in the The cloth-plate Z is secured by means of screws to the top of the shuttle-race e. This plate has a half-moon-shaped opening, which is partly closed by he needle-plate g, which is likewise screwed to the top of the piece 0. The remaining part of opening in the clothpla-te serves for removingfor inserting the shuttle, and is covered by the shuttle-plate a. This plate a partly rests o the s11 little-race, and partly on the two ears 1, Figs. 6 and 7, which are fastened to the lower side of the clothplate.

The straight end of the needle-plate q is beveled downward, so as to form a recess for the corresponding beveled side of the shuttlecover, on the opposite side of which there is a lock-hook, u, projecting downward. This hook has a sloped face, which, when the plate a is pressed down into its place, pushes the lever v aside against the tension of the spr n g 1 until the lever comes opposite the notch in the hook and catches into this notch, whereby the plate is locked and held in itsposition.

In forcing down the plate the lower cnd of the hook presses on the spring I and deflects it downward. The lever a" is pivoted to the bed-plate at 'v, and its inner end is turned up 1. at the inner side of the cloth-plate, which is notched out for the necessary throw of the lever. The turned-up part of the lever '12 serves as a thumb-piece for opening the shuttle-cover by turning the lever v so as to release the hook. As soon as the hook is released the small spring 1 throws the shuttle-plate up. In Fig. 9 the spring 1 is omi'ted.

To the front of the lower needle-bar guide is secured a thread-brake, 10, consisting of two loose disks carried by a pin projecting from a spring-arm, and passing through an aperture in the wall of the guide. The inner end of the pin presses against the needle-bar, which has its surface soshaped as to force said pin out- .ward and permit it to be moved inward to Over and partly around the two cams f f a cover or guard, s, is placed, and secured by a screw to the'bearing c of the shaft 0". On the top of this guard s the spool-winder'is placed, which is of the usual construction.

The bobbin-winder frame has a large hole in the middle, with a circular countersunk washer on the top. This washer has an oblong hole or slot, through which passes the shank of the screw for fastening the winder a to the guard s. The washer having an oblong hole, and being free to turn in its seat, the spool-winder can be adjusted in any horizontal direction.

The standard a has a projection, on, with a vertical dovetail-shaped groove, in which the slotted prism 76 slides vertically. This prism 70 carries the pivot-bearin g of the hand-wheel. The pin a passes through the slot in the prism and screws into the standard. The setscrew or tightening-screw k screws into the top of the prism, and rests with its lower end on the pina By means of this set-screw the prism, and with it thehand-wheel, are raised or lowered at will, for the purpose of tightening the chain orslacking it up. p

The chain-wheels have on their periphery triangular prismatic projections or teeth cast on at the proper distances, corresponding to the length of a chain-link. A groove is turnedin for receiving the links at right angles to the face of the wheel. The triangular form of the teeth causes the chain-gear to work without noise.

What I claim is-,

l. The two eccentrics r 1" in front of the shuttle-race, in combination with the feed-bar m, spring y, and th limb-screw m substantially as described.

2. The combination, with the spool-winder framehaving the central opening, of the washer having the oblong slot, and the clampingscrew for securing the winder-frame in position, substantially as described.

3. The combination, with the shuttle-cover, of the lever 1;, book a, supports 1, and spring 1 substantially as described.

CARL J UN KER. 

